The present invention regards protecting a workpiece during its manufacture or reconfiguration. More specifically the present invention regards reducing the probability of damaging a coating on a workpiece during the workpiece""s manufacture or reconfiguration by using a protective membrane.
Articles of manufacture are regularly coated for numerous and varying reasons. For example, they may be coated to protect them from the intrusive handling they can be subjected to during their manufacture and to protect them from the severe environmental conditions they can encounter after they are manufactured. In either circumstance, as well as in others, damage to the coating of a workpiece, resulting from the handling, mishandling or reconfiguration of the workpiece, is an unwanted result.
When the coating of a workpiece becomes scratched or otherwise damaged during its manufacture, the scratches can promote the deterioration of not only the coating but also the workpiece itself by exposing the workpiece""s surface to its surroundings. For instance, should the workpiece be employed in a corrosive environment, its errantly exposed surface would be more vulnerable to corrosion than if its coating were completely intact.
Moreover, the scratches and inconsistencies in the coating of a workpiece may also reduce the effectiveness of the finished product. For example, should the coating be used to uniformly deliver some type of releasable substance, inconsistencies in the coating can foster uneven and non-homogeneous delivery of the releasable substance to the deployed product""s final surroundings.
An expandable coated stent is one specific example of the coated workpieces described above. Expandable stents are tube-like medical devices designed to support the inner walls of a vessel or lumen within the body of a patient. These stents are typically positioned within a targeted lumen of the body and then expanded to provide internal support for the lumen. These stents may be self-expanding or, alternatively, may require external forces to expand them. In either case they are typically deployed through the use of a catheter of some kind. These catheters typically carry the stents at their distal end.
Due to the interaction of the stent with the inner walls of the lumen, stents have been coated to enhance their effectiveness. These coatings may, among other things, be designed to facilitate the acceptance of the stent into its applied surroundings or to facilitate the delivery of therapeutic to the lumen and its surroundings. When the coating is haphazardly applied or has somehow been removed during the stent""s manufacture, both the stent""s useable life span and its effectiveness can be reduced.
The coatings on these stent may be applied at various times during its life cycle including during its manufacture, during its placement onto the distal end of the delivery catheter, and contemporaneous with the medical procedure being performed. At each of these times the coating may be at risk of being scratched, damaged or otherwise removed from the surface of the stent. For example, during their manufacture, stents are often crimped onto the distal end of the delivery catheter. During this crimping the mechanical arms of a crimper may come in contact with the coating of the stent as the arms act to reduce the diameter of the stent. This compressive contact can scratch, indent, wipe-off or otherwise breach the integrity of the coating.
A method of protecting the coating on a reconfigurable coated workpiece having a first end and a second end is provided in one embodiment of the present invention. This embodiment includes providing an encasing hollow deformable membrane, positioning the first end of the reconfigurable coated workpiece adjacent to an entrance orifice of the membrane, enlarging the entrance orifice and the inside cavity of the membrane, inserting the reconfigurable coated workpiece into the enlarged entrance orifice and into the inside cavity, and decreasing the size of the inside cavity of the membrane until an inside surface of the cavity contacts the coating of the workpiece.
A system for delivering a coated reconfigurable medical implant to a target site is also provided in an alternative embodiment of the present invention. A system in accord with this embodiment includes a carrier device and a medical implant covered in a protective membrane wherein the medical implant is located at the distal end of the carrier device on an implant carrying region.
A medical stent in accord with another embodiment is also provided. A stent in accord with this embodiment may include a metallic frame that may be expandable from a first position to a second position, a polymeric layer coating at least a portion of the metallic frame, and an encasing hollow deformable membrane surrounding the polymer layer.